It is known that, in a large number of aircrafts, including those used for civil transport, the engine speeds are individually controlled by throttle control levers, respectively associated with said engines. Such throttle control levers, adapted to occupy several positions, are actuated either manually by pilots, or automatically. The current position of each of such throttle levers is detected by corresponding position sensors.
It is also known that to each of said throttle control levers, there are associated permanent artificial force gradient means (more particularly under the form of an antagonistic force to the shift of the corresponding lever), either of the mechanical type or of the electromagnetic type, with an engine.
However, it frequently happens that performance deviations occur between the artificial force gradient means associated with different throttle levers of an aircraft, whatever the type (mechanical or electromagnetic) of the force gradient means being used. Such performance deviations are mainly due to control, wear, ageing effects, environmental conditions (such as temperature or humidity), etc.
Such performance deviations generally result in positioning deviations for the levers one relative to the others upon being actuated by the aircraft pilots, resulting in a dissymmetry of the thrust control for the engines of the aircraft. Upon a cruising speed flight, such a thrust dissymmetry should be compensated by flight control surfaces, being able to induce parasitic drags, being disadvantageous for the fuel consumption of the aircraft.